Various methods of cooling molten aluminous abrasive have been disclosed in the prior art, such as casting on product lumps (U.S. Pat. No. 3,781,172), casting on metal balls, casting between metal plates, and casting into molten salts (published German Application No. 2,519,569). For reasons pointed out below, the first three named methods are not entirely satisfactory. The last named method suffers from the low thermal conductivity, specific gravity, and boiling point of the proposed fused salts.